SERVER-88205 did away with a number of redundant parses of the $db field on common command paths in mongod, but there are still a few other places where we parse it more than once. We should update these to reuse the already parsed $db if possible, either by caching the value once we parse it or by reusing the already-parsed value found in CommandInvocation::db().

A few places where this parsing is likely redundant:

• replica_set_endpoint_util.cpp
• killExhaust in session_workflow.cpp
• cluster_find_cmd.h
• cluster_pipeline_cmd_{s,d}.cpp
• Any command that inherits from BasicCommand (updating to TypedCommand will fix this for free)

When picking up this ticket, grep for "parseDbName" to find the various call sites.